Method of making slide fastener coils

Abstract

A method of making slide fastener coils is disclosed wherein coils of filamentary material are secured to adjacent edges of a pair of carrier tapes. Each coil of filamentary material is formed from a filament having a specially shaped cross section which is arranged in a mirror image relationship with respect to its adjacent filamentary coil. During formation of the filamentary coils, they are simultaneously wound on a mandrel having differently shaped surfaces which aid in the final shaping of each coil.

What is claimed is: 
     
       1. A method of forming a pair of coils for a slide fastener device comprising the steps of supplying a pair of continuous filaments having generally elliptical cross sections to a shaping station,   winding the filaments at the shaping station in opposite directions to form a pair of intermeshed coils,   shaping each convolution of each coil into four components including a bight element, first and second links extending from said bight element and a connector member extending from the first link of one convolution to the second link of an adjacent convolution, and   continuously changing the geometry of each convolution as it is being shaped by reorienting the major axis of its cross section whereby the first links are asymmetrically arranged relative to the second links.   
     
     
       2. The method as claimed in claim 1 wherein the reorientation of each bight element is accomplished by aligning its major axis so as to be generally parallel to a longitudinal axis defined by the intermeshed coils. 
     
     
       3. The method as claimed in claim 2 wherein the reorientation of each connector member is accomplished by aligning its major axis so as to be generally parallel to said longitudinal axis. 
     
     
       4. The method as claimed in claim 3 wherein the reorientation of each of the first and second links is accomplished by inclining their major axes relative to said longitudinal axis. 
     
     
       5. The method as claimed in claim 4 wherein the major axis of each first link is inclined at a different angle from the major axis of each second link. 
     
     
       6. The method as claimed in claim 1 wherein the connector members of one coil are formed by being wrapped around adjacent portions of the bight elements of the other coil. 
     
     
       7. The method as claimed in claim 1 wherein the filaments are wound under tension to assure the shaping of the convolutions and wherein the formed intermeshed coils are passed through a heating stage for permanently setting the same.